From 42132c543358cee9f7c3e9e9b15bb6c1063a608e Mon Sep 17 00:00:00 2001
From: Erik de Castro Lopo <erikd@mega-nerd.com>
Date: Tue, 1 Jan 2019 20:11:46 +1100
Subject: [PATCH] src/wav.c: Fix heap read overflow

This is CVE-2018-19758.

Closes: https://github.com/erikd/libsndfile/issues/435
[Retrieved (and backported) from:
https://github.com/erikd/libsndfile/commit/42132c543358cee9f7c3e9e9b15bb6c1063a608e]
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
---
 src/wav.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/wav.c b/src/wav.c
index 9d71aadb..5c825f2a 100644
--- a/src/wav.c
+++ b/src/wav.c
@@ -1,5 +1,5 @@
 /*
-** Copyright (C) 1999-2016 Erik de Castro Lopo <erikd@mega-nerd.com>
+** Copyright (C) 1999-2019 Erik de Castro Lopo <erikd@mega-nerd.com>
 ** Copyright (C) 2004-2005 David Viens <davidv@plogue.com>
 **
 ** This program is free software; you can redistribute it and/or modify
@@ -1146,6 +1146,8 @@ wav_write_header (SF_PRIVATE *psf, int calc_length)
 		psf_binheader_writef (psf, "44", BHW4 (0), BHW4 (0)) ; /* SMTPE format */
 		psf_binheader_writef (psf, "44", BHW4 (psf->instrument->loop_count), BHW4 (0)) ;
 
+		/* Loop count is signed 16 bit number so we limit it range to something sensible. */
+		psf->instrument->loop_count &= 0x7fff ;
 		for (tmp = 0 ; tmp < psf->instrument->loop_count ; tmp++)
 		{	int type ;
 
